US Guided Subclavian Lines

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Subclavian lines can be useful when accessing the internal jugular (IJ) or femoral vein is not ideal. For example, you may choose to avoid the IJ in patients who are wearing a c-collar, have a tracheostomy, or have trauma to the head and neck. In addition, some femoral sites are avoided due to pelvic trauma, a large pannus, or a contaminated inguinal region. Using ultrasound to place a subclavian central line can decrease procedure time as well as potential complications, such as pneumothorax, nerve injury, arterial cannulation, thoracic duct injury, hematoma, and hemothorax.

Anatomy: The Subclavian vein is a continuation of the axillary vein as it courses under the clavicle of the first rib and joins with the IJ. The subclavian vein is located inferior and anterior to the subclavian artery. The lung and pleural cavity are deep and interior to the subclavian vein.

There are 2 approaches to placing a subclavian central line: the supraclavicular approach and the infraclavicular approach.

For the supraclavicular approach stand at the head of the bed as if you were placing a central line in the IJ. Place your linear probe above the clavicle to visualize the vein in short axis (you can find the IJ first and trace it until it joins up with the subclavian). Visualize the vein and proceed with Seldinger technique, taking care to note where the pleura is in reference to the vein. You can try to avoid puncturing the pleura by aiming the needle at the rib just under the subclavian vein, so if you overshoot you will be stopped by the rib.

The infraclavicular approach can be done in short or long axis view. If done in long axis, place the probe in the infraclavicular fossa. Your needle in this approach is much more lateral when compared with the landmark-based approach. Identify the point where the axillary and cephalic vein joins with the subclavian and insert your needle past that junction. You will not be able to visualize the artery and vein simultaneously in this view, so use doppler or rotate the probe to short axis so that you can see both the artery and vein at the same time. Proceed with Seldinger technique.

Tip: shrugging the patient’s shoulder opens up a window to puncture the subclavian vein over the 1st rib. In a neutral position, the 1st clavicle lies over the vasculature. Raising the shoulder lifts the clavicle and opens up this space. In this position, if the needle doesn't hit the first rib it will often arch over the first lung, rather than puncture it.

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